In the directional drilling of oilwell boreholes, it is not uncommon for the drillstring to become mechanically stuck within the borehole. The recovery and replacement costs associated with a stuck drillstring are high. Accordingly, there is an interest in the art in developing methods for predicting the onset of drillstring sticking so that action may be taken to avoid the problem. Johancsik et al developed an interactive technique for the determination of torque and drag on a drillstring based upon the interaction between the borehole and the drillstring; "Journal of Petroleum Technology", June 1984, P987. In R.G. Whitten, "Application of Side Force Analysis and MWD to Reduce Drilling Costs", 1987 SPE/IADC Drilling Conference, a method for concentration of torque and drag effects in the bottom hole assembly (BHA) was suggested, and the concept of borehole severity as a single value measurement of the interaction between BHA and the borehole was introduced. This work suggested that mechanical sticking of the drillstring may be predicted based on the borehole severity profile and interpreted lithology taken from measured while drilling (MWD) gamma ray measurements and identified the direction of the borehole severity slope and the location of stabilizers relative to standing formations (determined from the gamma ray readings) as critical factors in determining the onset of drillstring sticking.